Early reflection detection using autocorrelation to improve robustness of speaker verification in reverberant conditions

Abstract

A speech signal captured by a distant microphone is generally smeared by reverberation, which severely degrades automatic speaker recognition performance. To improve system performance, an effective and robust method is proposed to extract features for speech processing. In this paper, a room impulse response is presumed to comprise of three parts: a direct-path response, early reflections and late reverberations. Since late reverberations are known to be a major cause of system performance degradation, this paper focuses on dealing with the effect of early reflection because the early reflections and their properties play a necessary role within the acoustics of an enclosure. The proposed method first estimates the early reflection using autocorrelation function from the presentation of speech signals in the first stage, the estimates are combined with an anechoic signal for use into training the system in the second stage. The employed method looks to be promising, achieving a substantial improvement in system performance relating to reduced equal error rate and detection trade-off, especially at longer reverberation time.